Because adhesion receptors connect ECM to intracellular filaments, they transmit forces between these structures. These may be intracellular forces from myosin that act on the surrounding ECM, or external forces acting on the cell. Integrins are involved in “measuring” the mechanical properties of the ECM, which critically govern cell behavior.
Regulation of cell behavior by adhesion to extracellular matrix (ECM) is a fundamental fact of multicellular life. Virtually every cell in vertebrates spends at least a portion of its life cycle adhered to ECM, and this interaction critically regulates cell survival, growth, gene expression and function. Integrins are the major membrane receptors that mediate adhesion of cells to ECM. In doing so, they connect the actin cytoskeleton inside the cell to the ECM to provide mechanical integrity. My lab is among those that, in the late 1980’s, showed that integrins also transduce signals. These signals are complex and varied, and appear to mediate many if not most of the regulatory effects of ECM.